batman-adv: Prefix gateway-client non-static functions with batadv_

batman-adv can be compiled as part of the kernel instead of an module. In that
case the linker will see all non-static symbols of batman-adv and all other
non-static symbols of the kernel. This could lead to symbol collisions. A
prefix for the batman-adv symbols that defines their private namespace avoids
such a problem.

Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c
index 74175c2..92d3ea3 100644
--- a/net/batman-adv/unicast.c
+++ b/net/batman-adv/unicast.c
@@ -294,7 +294,7 @@
 
 	/* get routing information */
 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
-		orig_node = gw_get_selected_orig(bat_priv);
+		orig_node = batadv_gw_get_selected_orig(bat_priv);
 		if (orig_node)
 			goto find_router;
 	}